I'll run AV software on my Mac if/when there is a credible virus threat out there that can infect a fully up to date Mac OS system. PC users face many thousands of credible threats, so they should be running AV software.

I know AVG. I run a NAT/SPI firewall router which is pretty secure. I also don't download or install anything I don't want to use. I also don't use IE, and I don't use software that needs codecs or any other third party download.

I am safe, therefore I pretty much dont ever get viruses. Haven't had one in 7 years, and the last one I had was because my roomate at the time was using bearshare and got me infected on my computer, it wasn't even me.

There is already credible proof of concept of a codec virus for QT for OS X. So, there is already proof that it can be done. It just is not a huge threat at this point in time. I'd say 5 years is way too long. Apple is gaining market share every month and there would be a lot of bragging rights to any hacker who developed the first wide spread virus for OS X. It is bound to happen sooner or later. Most likely through a codec install or some other type of social engineering scheme, so it won't self propagate but it could be distributed all over the place on the world wide web.

A very, very heavy condom or gun they slows you down to a crawl, even though you don't need it.

My experience with Clam AV is that it is not too resource hungry. I think it only used like a 5MB memory fingerprint which isn't that bad. I could be confusing it with another product though.

I mean its not like Unix memory management can't handle it. you make it sound like you load AV software on your Mac and it will run like a 386.

Well, I do run AV software on my Mac (despite the naysayers, Norton, which has not troubled me at all). But that's mainly because I regularly transfer files to and from my school computers and don't want to take the tiniest chance of propagating something there.

As for native Mac infections, the last free-breathing virus I remember was Scores, and something in Hypercard, both around 1988 and both fairly mild. After that, I've come across the usual piggyback Word Macro viruses occasionally...but not in a long time. Not that there haven't been loopholes in Mac security – just that not enough hackers have shown the interest, skill, and alacrity to exploit them.

On the other hand, I remember Melissa virtually shutting down my then Windows-based software company.